Oro-nasal face mask with improved sealing cuff



July 11, 1967 v. R. BENNETT 3,330,273

ORG-NASAL FACE MASK WITH IMPROVED SEALING CUFF Filed Oct. 15, 1964 I 2 Sheets-Sheet 1 INVENTOR 38 RAY BENNETT BY 7 Wm; m M? aiee ea" Z/Zecfiz:

4 V AITOENEYYS,

July 11, 1967 v. R. BENNETT 3,330,273

ORO-NASAL FACE MASK WITH IMPROVED SEALING CUFF Filed Oct. 15, 1964 2 Sheets-Sheet 2 FIG-l5 INVENTOR. V- RAY BENNETT 4M, Zfiz, 552a J QM nrromvsys United States Patent 3,330,273 ORO-NASAL FACE MASK WITH IMPROVED SEALING CUFF V. Ray Bennett, Yucca Valley, Calif assignor to Puritan Compressed Gas Corporation, Kansas City, Mo., a corporation of Missouri Filed Oct. 15, 1964, Ser. No. 494,121 13 Claims. (Cl. 128-146.7)

This invention relates to an improved oro-nasal face mask for respiratory use, and more particularly to such a mask embodying an improved sealing cuff for effecting a seal between the perimeter of the mask and the face and for cushioning the force exerted by the mask against the face.

The sealing cuff of the invention finds particularly useful application with an oro-nasal mask, and, for this reason, it is described in conjunction with an improved mask of this type. It is to be noted at the outset, however, that the cuff may be used to advantage with other devices adapted to be positioned in sealing engagement with portions of the body, such as respiratory mouth pieces, bathing caps and ear-covering devices. Thus, the illustration and description of the cuff in conjunction with this one type of device is not intended to be limitative.

Ore-nasal masks are conventionally used in high altitude flying for supplying oxygen. It is readily apparent that an effective seal is essential in such a use. Any appreciable leakage could produce potentially disastrous consequences. In further regard to this use, it is noted that certain types of masks, notably most of those having an inflated cuff, are adversely affected by changes in atmospheric pressure correspondin g to changes in altitude.

Such masks also have widespread application in the medical field. Breathing gas, which often has an anesthetic or medicament added, is administered to a patient. In many cases it is essential to accurately meter the volume of gas being supplied to the patient. In these cases any leakage, of course, adversely affects the accuracy of the measurement.

Another use for oro-nasal masks in the medical field is in administering intermittent, positive pressure-breathing therapy, commonly known as IPPB, to patients having a wide variety of respiratory disorders. In IPPB therapy, the lungs are inflated under a control pressure during the inspiration phase of the breathing cycle. This in turn results in distention of the lung-thorax system somewhat more than in normal inspiration, and hence in more uniform and thorough alveolar aeration. Here again, it will be readily appreciated that effective sealing is essential. Any leakage will prevent the desired control pressure from being applied to the lungs so that full ventilation is not achieved.

In addition to the necessity of good sealing, comfort to the wearer is an extremely important factor, both from psychological and physiological standpoints. Where such a mask is used in conjunction with high altitude flying and in many medical applications, as in administering IPPB therapy, it must be worn for prolonged periods. In the event excessive force is applied against limited facial areas in order to achieve over-all sealing, damage to the facial tissue is likely to occur. Furthermore, severe apprehension frequently stems from the physical discomfort.

Masks heretofore available have not been entirely successful in meeting these requirements of sealing and comfort. It has been found that with a substantial percentage of users the facial contours differ so greatly from the design standard that in some cases sealing cannot be achieved. In other cases the mask is pressed so tightly against raised facial areas in order to seal in relatively 33393273 Patented July 11, 1967 depressed areas as to cause damage to the tissue and bring about severe discomfort and apprehension.

A further problem inherent in the masks of the prior art is in maintaining the desired conditions of sanitation. Particularly in medical usage, it is often the case that masks are used by many different patients. Thus, it will be readily understood that it is import-ant that they be thoroughly cleaned after each use. Certain designs heretofore available have made it extremely diflicult, at best, to achieve proper cleaning.

In view of the foregoing, it is a primary object of the invention to provide an improved oro-nasal face mask which obviates the problems of the prior art.

A more specific object is to provide an oro-nasal mask for general use with an improved sealing cuff around its perimeter capable of compensating for substantial irregularities in the facial contour to afford a highly effective seal between the perimeter of the mask and the face of the wearer.

A related object is to provide a mask of the type described embodying a cuff of unique construction whereby mechanical resilience and system pressure in the mask acting on a portion of the cuff combine and afford a highly effective seal.

Another object is to provide a mask of the type described, further characterized in that it may be worn comfortably by persons with a wide variety of facial contours.

Another object of this invention is to provide a mask of the type described in which the cuff is constructed and arranged so that the mask is effectively sealed and may be worn comfortably while subjected to substantial changes in atmospheric pressure, as would be encountered in high altitude flying.

A further object is to provide a mask of the type described which is readily adapted to be thoroughly cleaned following use.

It is another object of the invention to provide an improved oro-nasal mask, having a face piece of narrow width and profile, so as to afford a relatively small breathing chamber and thereby minimize re-breathing of expired gas.

A still further object is to provide an improved mask of the type described capable of accomplishing all of the foregoing objects, yet which is relatively simple in construction and capable of being economically mass produced.

Still another object is to provide an improved sealing cuif for effecting good sealing between a cover member and a portion of the body engageable by such member, even where substantial irregularities are encountered in the surface of the body portion.

These and other objects, features and advantages of the invention will be better understood by referring to the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevational view of the mask of the invention positioned for use on the face of the wearer;

FIGURE 2 is a front elevational view, similar to FIG- URE 1, with a portion of the supply conduit cut away and removed in order to show underlying parts more clearly;

FIGURE 3 is a perspective view of a spider on the forward portion mask and portions of a harness used to hold the mask in position for use;

FIGURE 4 is a vertical sectional View taken along the line 4-4 of FIGURE 2;

FIGURE 5 is a horizontal sectional view taken along the line 5-5 of FIGURE 2;

FIGURE 6 is a fragmentary sectional view on an enlarged scale taken along the line 6-6 of FIGURE 5;

FIGURES 7 and 8 are fragmentary sectional views, similar to FIGURE 6, except that the sealing cuff is shown under different conditions of use;

FIGURE 9 is a fragmentary sectional view, similar to FIGURE 6, of a modified form of the sealing cuff of the invention;

FIGURES 10 and 11 are fragmentary sectional views of the cuff shown in FIGURE 9 in conditions of use corresponding to FIGURES 7 and 8, respectively;

FIGURES 12 is a fragmentary sectional view, similar to FIGURE 6, of still another modified form of the cuff of the invention;

FIGURES 13 and l4are further fragmentary sectional views of the cuff illustrated in FIGURE 12 in conditions of use corresponding to FIGURES 7 and 8; and

FIGURE 15 is a vertical sectional view through the cuff taken in the direction of the arrows 15 in FIGURE 1.

Referring to the drawings and in particular to FIGURES 1 and' 2, the mask of the invention, designated by the reference numeral 10, includes generally a face piece 12, a sealing cuff 14, an attachment harness 16, and a connector assembly 18. The latter member is adapted for connection to a combined inlet-outlet conduit of suitable respiration apparatus.

- The face piece 12 is shaped to cover the frontal portion of the face, including the nose and mouth. It is sized to extend from the bridge of the nose down toa location just under the chin. The width increases from a minimum adjacent the nose to a maximum adjacent the mouth, and then progressively decreases toward its lower end.

The marginal edge 22 of the face piece around its entire perimeter is shaped to conform generally to the surface contour of the face of'an average person. The mask is intended for general use and, therefore, the shape is determined by the characteristics of an average person.

When the face piece is positioned over the nose and mouth, the rearward side of the marginal edge 22 is in close prox- 'imity to the adjacent surface of the face. Actual contact is, of course, prevented by the resilient, deformable sealing cuff 14 which, in addition, provides for perimeter seal ing notwithstanding the known differences in facial contour from person to person.

From its marginal edge 22 the face piece 12 projects forwardly and converges centrally to afford a cover-like central portion 24. The forwardmost end 25 of the face piece 12 is flattened and provided with an inlet-outlet passage 26. When the mask is positioned for use, as in FIGURES l and 2, the face piece 12 and the underlying frontal portion of the face cooperate to define the boundaries of a breathing chamber 28. Preferably, this chamber is relatively small in volume in order to minimize the re- I breathing of expired gas. Provision of a small breathing chamber 28 is achieved by making the face piece 12 of relatively narrow profile and width.

' ,The face piece 12 is preferably formed with a rela- 4 ly away therefrom and then inwardly at an orientation generally parallel to the adjacent rearward surface of the edge 22. The latter portion of the flap presents a rela-.

tively flat surface for sealing engagement with a face;

In order to initially position the flap for facial engagement and to maintain its position, as well as to afford the cushioning effect desired, the back-up band 32 is provided. It comprises a spring-like and hook-shaped element formed of a resilient, flexible material, and is disposed be tween the facial flap 30 and the rearward surface of the marginal edge 22. In the presently preferred embodiment shown in'section in FIGURES 4 to 8, the band 32 is hook-shaped and oriented oppositely to the flap 30 so as to cooperate with the latter to form a semi-closed cuff.

side of the-facial flap 3G, to support it adjacent its ter-' minal end and finally back towards'the edge 22. The terminal end of the band 32 in its normalunfiexed condition tively stiff and transparent plastic material. Plastic is preferred from the standpoint that it is strong and durable, impermeable to-gas, easily cleaned and may be easily molded into the desired shape. However, other materials, such as metals, may be used.

In order to achieve sealing between the marginal edge 22 of the face piece 12 and the face and for cushioning engagement for comfort of the wearer, the sealing cuff relatively thin member formed of a flexible and, preter ably, at least semi-resilient material. It extends from a location adjacent the marginal edge 22, curving rearward- (FIGURE 6) stops short of the opposite wall of the cuff,

which in this case is formed by a portion of the attach-' ment flange 34.

Use of the back-up band 32 enables the facial flap I sealing engagement with the face, as will be brought out below.

Further advantage may be gained by making the flap '30 of a tapered configuration, as illustrated in FIGURE 6,

i.e., progressively thinner in its face-engaging portion from its inner towards its terminal end. This further enhances the ability of the flap to conform to irregularities, both.

mechanically and under the influence of system. pres sure, yet it still has the same desired resistance to bending or flattening in its curved region, designated by the numeral 30'. Similarly, the back-up band may be formed so that its support portion 38 is tapered or progressively thinner from the base portion towards its terminal end,

although not to as great an extent as the flap. Optimum spring action from this member, which is, in effect, cantilevered, can be obtained in this manner.

The interior of the cuff 14 is vented to the mask chamber 28 by apertures 40, illustrated in FIGURES 5, 6 and a 15. Preferably, two such apertures, located at the top and bottom of the mask, are provided. They permit pressure within the breathing chamber 28 to act against the underside of the facial flap 30 to assist in obtaining sealing. In addition, they permit water trapped within the cuff following cleaning to drain out.

The cuff 14 is secured to the marginal edge 22 of'the face piece 12 by any suitable means. For cleaning .pur-

poses, a detachable connection is desired. To this end,

the flange 34 is formed with a slot 42 for receiving the edge. The perimeter of the flange portion forming the slot is made slightly smaller in over-all perimeter than the perimeter of the face piece. Installation is achievedsimply by stretching the flange slightly to position the slot 42. over the edge. In order to insure a secure, gas-tight connection, the wall thickness of the edge 22 on the for-.

ward side is tapered to afford an inwardly facing stop shoulder 44. The mating surface of the flange 34 is'in turn formed with a correspondingly shaped groove 46 for receiving the shoulder.

For convenience of manufacture, the attachment flange 34 is formed integrally with thefacial flap 30. The backup band 32, on'the other hand, is here formed separately from the flap 30 and interposed between the rearward surface of the marginal edge 22 and the adjacent portion' of the flange 34. Attachment of the band to the flange of the interface 48 to make the cuff 14 a unitary structure is achieved by bonding with a suitable adhesive or the like.

Preferably, the entire cuff is formed of a resilient and highly flexible material, such as plastic or rubber. Such materials have the desired physical characteristics and, in addition, are durable and easily formed into the desired shapes. In some applications, it may be desirable to form the back-up band of a slightly stiffer material in order to obtain the required spring action. This same result may often be achieved by appropriately varying the thicknesses of the various parts.

When the mask is positioned for use as in FIGURES 1 and 2, the sealing cuff 14 accomplishes the desired sealing by virtue of the combined effects of the mechanical resilience of the back-up band 32 and facial flap 30, and the mask pressure exerted against the flap. The face-engaging portion of the flap 30 is initially positioned for sealing engagement with the face by the band 32. The cuff is shown in FIGURE 6 in a normal or substantially undeformed condition as would exist prior to facial contact. When the mask is pressed firmly against the face to establish pressure sealing, the cuff 14 flattens slightly toward the condition illustrated in FIGURE 7. This initial flattening causes bending of the flap in the region 30 and bending of the band 32 in the curved region 38 of its support portion. Such bending, and hence flattening of the cuff, is yieldably resisted by the resilience of the band 32 and, to a lesser extent, of the flap 30.

Should further force be applied in pressing the mask against the face, the terminal end of the band pivots sufficiently to engage the opposite wall of the cuff 14 (here the surface of the attachment flange 34). Upon such band engagement, further flattening of the cuff produces lateral bulging of the band with additional resistance imposed by virtue of bending of the band in the region 38", as well as in the region 38', being required. The condition of the cuff 14 following this further flattening is illustrated in FIGURE 8.

In the event the marginal edge 22 of the face piece 12 were shaped to conform exactly to the contours of the face, the cuff 14 would be deformed substantially to the same extent around the entire perimeter of the face piece 12. In such an optimum situation, a good balance between sealing and comfort is attained with deformation of the cuff approximately to the extent illustrated in FIGURE 7. In providing a mask suitable for general use, such close tolerances are not possible, and the cufl would be deformed in localized areas around its perimeter to different extents, between the conditions illustrated in FIG- URES 6 and 8. In cuff areas corresponding to depressed facial areas, the cuff would more nearly approach the condition illustrated in FIGURE 6, whereas in raised facial areas, it would more nearly approach the condition illustrated in FIGURE 8.

Once the mask 10 is in place and system pressure is delivered to the breathing chamber 28 through passage 26, the seal is further enhanced because of pressure being exerted on the underside or forward face of the sealing flap 30 to urge it tightly against the face (FIGURES 7 and 8). The vent apertures 40 insure that system pressure is applied to the entire surface of the flap. As set forth above, such pressure scaling is dependent upon primary sealing first having been established by the mechanical resilience of the cuff 14.

It will be appreciated that the cuff of the invention is readily capable of compensating for substantial irregularities in facial contour to afford an effective seal. Considerable travel occurs in flattening from the condition of FIGURE 6 to that of FIGURE 8. Moreover, the mask is worn comfortably even where substantial variations in localized areas, as exemplified by the showings of FIG- 6 URES 6 and 8, are present. This stems from the fact that the facial flap, being thin and formed of a highly flexible material, has a very soft and pliable feel. In addition, the resistance to flattening of the cuff is spring-like, or progressively increases with the degree of flattening. Since the cuff is vented to the breathing chamber 28, changes in atmospheric pressure have no detrimental effect on its performance. Accordingly, the mask 10 is especially well suited for high altitude flying.

Two alternate embodiments of the cuff invention, designated by the reference numerals 60 and 70, are illustrated in FIGURES 9 to 11 and 12 to 14, respectively. In each of these latter embodiments, the back-up band is oriented differently in one case and configurated differently in another case than the band 32 of the embodiment previously described, but the function of the cuff is the same.

The end 60 has a back-up band 62 that is hook-shaped and cantilevered like the band 32 previously described, but it faces the same way as the facial flap; that is, its support portion 64 initially curves outwardly and rearwardly away from the marginal edge 22 of the face piece, then inwardly parallel to the face-engaging portion of the facial flap and finally back toward the edge. The base 63 of the band is in this case bonded to the rearward surface of the attachment flange 34. The resulting cuff 60 is open as opposed to the semi-closed cuff 32.

In use, the cuff 60 functions identically to the cuff 14, with FIGURES l0 and 11 corresponding to FIGURES 7 and 8 insofar as flattening of the cuff against the face is concerned. In FIGURE 10, simple bending of the facial flap 30 in the region 30' and of the band 62 in the region 64' to pivot the terminal end of the support portion 64 into engagement with the opposite wall of the cufl? has taken place. Still further flattening has taken place in the condition of FIGURE 11, producing lateral bulging of the band 62 against the added resistance to bending in the region 64".

Vent apertures 66, located at the top and bottom, as in FIGURE 15, insure that system pressure acts on the underside of the flap 30' for sealing and that any water trapped during cleaning may be drained.

The cuff 70 includes a back-up band 72 with two hookshaped and cantilevered support portions 74 and 76. A base portion 73 is bonded to the attachment flange and the two support portions 74 and 76 extend from its opposite ends and curve toward and face one another.

Again the functioning is essentially the same as the other embodiments, with FIGURES 13 and 14 corresponding to FIGURES 6 and 8. Flattening initially causes bending of the flap 30 in the region 30 and of the support portions 74 and 76 in their regions 74' and 76', respectively, to pivot the terminals ends of such portions inwardly. Yieldable resistance is imposed by resilience of the material forming these parts. Once the terminal ends of the support portions 74 and 76 contact the opposite wall of the cuff, as in FIGURE 13, further flattening necessitates lateral bulging of the support portions. Added resistance is imposed since bending also takes place in the regions 74" and 76". Vent apertures 78 are again provided for the purposes previously indicated. This latter embodiment may prove especially advantageous where greater cushioning or resistance to flattening is desired.

The mask 10 is held in place on the face of the wearer by the harness assembly 16. It includes a spider 80 and a head harness 82. The spider 80 comprises an annular ring 84 having four radially projecting lugs 86 at angularly spaced locations. The ring 84 is positioned around the inlet-outlet passage 26 on the forward end 24 of the face piece, and is held in place by the connector assembly 18.

The harness 82 may be of any suitable configuration for comfort, provided it is arranged to hold the mask firmly against the face. In the illustrative case, it includes a pair of straps 88, one of which extends above and the other below the years. The two straps are joined just behind the ears by a pair of webs 90. At the ends of these straps,'holes 92 are provided for receiving the lugs on the spider in the manner illustrated in FIG- URE 3. To enable adjustment for different head sizes, a plurality of holes 92 are provided in each strap.

For the purpose of supplying and exhausting gas from the breathing chamber 28 and for securing the spider 80in position, the connector assembly 18 is provided. The assembly includes a tubular sleeve 94 of a diameter just slightly greater than that of the inlet-outlet passage 26. The rearward end 96 of the sleeve-is necked down so as to be receivable within the passage and to afford an annular rearwardly facing shoulder 98 at the juncture. Referring to FIGURES 4 and 5, it may be seen that the spider 80 is held in place by virtue of the ring 84 being interposed between the shoulder 98 and the forward end of the face piece. To hold the assembly together and afford a sealed connection, a resilient, deformable washer 100 is disposed around the sleeve and against .the face piece and a nut 102 is threaded on the correspondingly threaded end of the sleeve. Connection of the mask to suitable respiration apparatus is achieved by simply slipping the end of the inlet-outlet conduit 20 over the forward portion of the sleeve 94, as shown in FIGURE 4.

While certain embodiments of the invention have been illustrated and described in considerable detail, it will be understood that is only by way of illustration, and that numerous changes in the details of the construction and arrangements of the various parts may be made without departing from the spirit and scope of the invention.

I claim:

1. An oro-nasal mask, comprising: a face piece shaped to cover the nose and mouth, and having a forwardly projecting central portion defining a breathing chamber with an inlet-outlet passage, and a marginal edge conforming generally to the surface contour of the face; and a sealing cuff extending around said face piece at said marginal edge, said cuff providing in cross-section,

' a thin, flexible flap extending rearwardly away from said marginal edge and then inwardly generally parallel to the adjacent surface of said marginal edge of spacing therefrom to present a flat surface adapted for sealing engagement with the face, and spring means including a band 'of resilient, flexible material cantilevered adjacent one end from a location adjacent said marginal edge and having a support portion disposed between said mar: ginal edge and said face-engaging flap portion and. at spacing therefrom in engagement therewith and extending along the underside of the latter to position said face-engaging fiap portion for such sealing engagement and yieldably resist movement thereof toward said marginal edge.

. 2. An oro-nasal face mask, comprising: a face piece shaped to cover the nose and mouth, and having a forwardly projecting central portion defining a breathing chamber with an inlet-outlet passage, and a marginal edge conforming generallyto the surface contour of the face; and a continuous sealing cuff secured to and extending around said face piece at said marginal edge, said cufi providing in cross section a thin, flexible facial flap curving rearwardly away from said marginal edge and then inwardly generally parallel to the adjacent surface of said marginal edge at spacing therefrom to present a flat surface adapted for sealing engagement with the face, and.

a hook-shaped 'back-up band formed of a thin, re-

. silient, flexible material and having a base portion adjacent said marginal edge and a support portion curving rearwardly away from said marginal edge and then back 1 toward the same, said support portion being disposed inshaped to cover the nose and mouth, and having a forwardly projecting central portion defining a breathing chamber with an inlet-outlet passage, and a marginal edge conforming generally to the surface contour of the face; and a unitary sealing cuff secured to and extending around said face piece at said marginal edge, said cuff providingin cross section a relatively thin, flexible facial flap curving rearwardly away from said marginal edge and then inwardly generally parallel to the adjacent surface of said marginal edge at spacing from the opposite wall of said cuffto present a flat surface for sealing engagement with the face, and a back-up band formed of a thin resilient, flexible material and having a base portion adjacent said marginal edge and a support portion integral with said base portion that initially curves rearwardly away from said marginal edge, then extends along the underside of said face-engaging portion of said facial flap in engagement therewith, and finallycurves back toward said marginal edge with its terminal end stopping short of the opposite Wall of said cuff, whereby movement of the face-engaging portion of said flap toward said marginal edge upon 'said' mask being pressed'firmly against the face is yieldably resisted initially by the bending of said band to pivot said terminal end into enga'ge-.

ment with the opposite wall of said cuff and, thereafter, by lateral bulging of said band;

5. An oro-nasal face mask comprising: a face piece shaped to cover the nose and mouth, and having a forwa rdly projecting'central portion defining a breathing chamber with an inlet-outlet passage, and a marginal edge conforming generally to the surface contour of the face; and a continuous sealing culf formed of a resilient, flexible material extending around said face piece at said marginal edge and having a substantially uniform cross section along its entire length, said cuff providing in cross section attachment means for securing said cuif to said face piece, a thin facial flap integral with said attachment means and extending rearwardly away therefrom and then inwardly generally parallel to the adjacent surface of said marginal edge at spacing therefrom to its terminal end so as to present a flat surface for sealing engagement with the face and a thin spring-like and hook-shaped back-up band having a base portion secured to said attachment means adjacent said marginal edge and a support portion cantilevered from said base portion and extending rear-- wardly, then along the underside of said face-engaging portion in engagement therewith at a location spaced outwardly of the terminal end of said flap and finally back toward said marginal edge with its terminal end stopping short of the opposite wall of said cuff.

6. The subject matter of claims further characterized in that the thickness of said support portion of said backup band tapers from a maximum adjacent said base portion we minimum adjacent said terminal end.

7. The subject matter of claim Sfurther characterized in that said attachment means detachably secures said cufi to said face piece. 7

'8. An pro-nasal face mask, comprising: a'face piece V shaped to cover the nose and mouth, and having a forwardly projecting central portion defining a breathing chamber with an inlet-outlet passage, and a marginal edge conforming generally to the surface contour of the face; and a sealing cuff extending around said face piece at said marginal edge, said cuff providing in cross section attachment meansfor securing said cuff to said face piece, a

thin resilient, flexible facial flap connected to said attachment means and curving rearwardly away from said mar- 4. An ore-nasal face mask, comprising: a face piecejacent surface of said marginal edge at spacing therefrom to its terminal end so as to present a flat surface adapted for sealing engagement with the face, and a hook-shaped back-up band formed of a thin resilient, flexible material and having a base portion connected to said attachment means adjacent said marginal edge and a support portion curving initially rearwardly and inwardly away from said marginal edge, then outwardly along the underside of said face-engaging portion of said facial flap at spacing from said marginal edge, and finally forwardly back toward said marginal edge with its terminal end stopping short of the opposite Wall of said cuff, said support portion engaging the underside of said face-engaging portion at a location spaced outwardly of said terminal end to position the latter for such sealing engagement.

9. An oro-nasal face mask, comprising: a face piece shaped to cover the nose and mouth, and having a forwardly projecting central portion defining a breathing chamber with an inlet-outlet passage, and a marginal edge conforming generally to the surface contour of the face; and a sealing cuff extending around said face piece at said marginal edge, said cuff providing in cross section attachment means for securing said cuff to said face piece, a thin resilient, flexible facial flap connected to said attachment means and curving rearwardly away from said marginal edge and then inwardly generally parallel to the adjacent surface of said marginal edge at spacing therefrom to its terminal end so as to present a flat surface adapted for sealing engagement with the face, and a back-up band formed of a thin resilient, flexible material and having a base portion connected to said attachment means adjacent said marginal edge and a support portion curving initially rearwardly and outwardly away from said marginal edge, then inwardly along the underside of the face-engaging portion of said facial flap at spacing from said marginal edge, and finally forwardly back toward said marginal edge with its terminal end stopping short of the opposite Wall of said cufiF, said support portion engaging the underside of said face-engaging portion at a location spaced outwardly of said terminal end to position the latter for such sealing engagement.

10. An oro-nasal face mask, comprising: a face piece shaped to cover the nose and mouth, and having a forwardly projecting central portion defining a breathing chamber with an inlet-outlet passage, and a marginal edge conforming generally to the surface contour of the face; and a sealing cuff extending around said face piece at said marginal edge, said cuff providing in cross section attachment means for securing said cuff to said face piece, a thin flexible facial flap connected to said attachment means and extending rearwardly away from said marginal edge and then inwardly generally parallel to the adjacent surface of said marginal edge to present a flat surface adapted for sealing engagement with the face, and a back-up band including a base portion connected to said attachment means adjacent said marginal edge and a pair of hookshaped support portions initially extending rearwardly away from said base portion at laterally spaced locations, then toward one another along the underside of said face-engaging portion of said facial flap and finally back toward said base portion, whereby said band positions said face engaging portion of said facial flap for such sealing engagement and yieldably resists flattening of said cuff toward said marginal edge.

11. The subject matter of claim 10 including means on said band for providing constant communication between said breathing chamber and the entire underside of said face-engaging portion of said facial flap.

12. A sealing cuff for use with a member for covering a body portion to afford a perimeter seal and to cushion the force of engagement, comprising in cross-section: means adapted for attaching said cuff to said cover member; a flap formed of a thin, flexible material connected to said attachment means and extending therefrom to present adjacent its terminal end a flat sealing surface for engagement with said body portion; and a back-up band formed of a thin resilient, flexible material cantilevered from said attachment means, said band including a base portion connected to said attachment means and a spring-like support portion curving away from said attachment means and extending along the underside of the engaging portion of said flap and finally extending back toward attachment means, said support portion being engageable with the underside of said flap to yieldably resist movement of the latter toward said attachment means.

13. An oro-nasal face-mask, comprising: a face piece shaped to cover the nose and mouth, and having a forwardly projecting central portion defining a breathing chamber with an inlet-outlet passage, and a marginal edge conforming generally to the surface contour of the face; and a sealing cuff extending around said face piece at said marginal edge, said cuff providing in cross-section attachment means for securing said cuff to said face piece, a thin resilient flexible facial flap extending rearwardly away from said marginal edge and then inwardly generally parallel to the adjacent surface of said marginal edge at spacing therefrom to present a flat surface adapted for sealing engagement with the face, and a spring-like band of thin resilient, flexible material cantilevered from said attachment means and having a support portion disposed between said marginal edge and the face-engaging portion of said facial flap and extending along the underside of said flap at spacing from said marginal edge for yieldably resisting movement toward said marginal edge, the cuff being arranged whereby system pressure within said breathing chamber acts uniformly on the underside of said face-engaging portion of said flap to urge it into tight sealing engagement with the face.

References Cited UNITED STATES PATENTS 577,956 3/1897 Henderson 128-146 902,961 11/1908 Goodnow 128-146 2,263,063 11/1941 Allen 52-717 2,546,049 3/ 1951 Weaver et al. 49-494 2,555,780 6/1951 Bright 49-490 2,647,792 8/ 1953 Flemming 49-496 2,875,757 3/ 1959 Galleher 128-146 2,931,356 4/1960 Schwarz 128-146 2,969,252 1/ 1961 Gruver 49-499 RICHARD A. GAUDET, Primary Examiner. K. L. HOWELL, Assistant Examiner. 

1. AN ORO-NASAL MASK COMPRISING: A FACE PIECE SHAPED TO COVER THE NOSE AND MOUTH, AND HAVING A FORWARDLY PROJECTING CENTRAL PORTION DEFINING A BREATHING CHAMBER WITH AN INLET-OUTLET PASSAGE, AND A MARGINAL EDGE CONFORMING GENERALLY TO THE SURFACE CONTOUR OF THE FACE; AND A SEALING CUFF EXTENDING AROUND SAID FACE PIECE AT SAID MARGINAL EDGE, SAID CUFF PROVIDING IN CROSS-SECTION, A THIN FLEXIBLE FLAP EXTENDING REARWARDLY AWAY FROM SAID MARGINAL EDGE AND THEN INWARDLY GENERALLY PARALLEL TO THE ADJACENT SURFACE OF SAID MARGINAL EDGE OF SPACING THEREFROM TO PRESENT A FLAT SURFACE ADAPTED FOR SEALING ENGAGEMENT WITH THE FACE, AND SPRING MEANS INCLUDING A BAND OF RESILIENT, FLEXIBLE MATERIAL CANTILEVERED ADJACENT ONE END FROM A LOCATION ADJACENT SAID MARGINAL EDGE AND HAVING A SUPPORT PORTION DISPOSED BETWEEN SAID MARGINAL EDGE AND SAID FACE-ENGAGING FLAP PORTION AND AT SPACING THEREFROM IN ENGAGEMENT THEREWITH AND EXTENDING ALONG THE UNDERSIDE OF THE LATTER TO POSITION SAID FACE-ENGAGING FLAP PORTION FOR SUCH SEALING ENGAGEMENT AND YIELDABLY RESIST MOVEMENT THEREOF TOWARD SAID MARGINAL EDGE. 